 /*******************************************************************************
  * Copyright (c) 2003, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.runtime.jobs;

 /**
  * Callback interface for clients interested in being notified when jobs change state.
  * <p>
  * A single job listener instance can be added either to the job manager, for notification
  * of all scheduled jobs, or to any set of individual jobs. A single listener instance should
  * not be added to both the job manager, and to individual jobs (such a listener may
  * receive duplicate notifications).
  * </p><p>
  * Clients should not rely on the result of the <code>Job#getState()</code>
  * method on jobs for which notification is occurring. Listeners are notified of
  * all job state changes, but whether the state change occurs before, during, or
  * after listeners are notified is unspecified.
  * </p><p>
  * Clients may implement this interface.
  * </p>
  * @see JobChangeAdapter
  * @see IJobManager#addJobChangeListener(IJobChangeListener)
  * @see IJobManager#removeJobChangeListener(IJobChangeListener)
  * @see Job#addJobChangeListener(IJobChangeListener)
  * @see Job#getState()
  * @see Job#removeJobChangeListener(IJobChangeListener)
  * @since 3.0
  */
 public interface IJobChangeListener {
     /**
      * Notification that a job is about to be run. Listeners are allowed to sleep, cancel,
      * or change the priority of the job before it is started (and as a result may prevent
      * the run from actually occurring).
      *
      * @param event the event details
      */
     public void aboutToRun(IJobChangeEvent event);

     /**
      * Notification that a job was previously sleeping and has now been rescheduled
      * to run.
      *
      * @param event the event details
      */
     public void awake(IJobChangeEvent event);

     /**
      * Notification that a job has completed execution, either due to cancelation, successful
      * completion, or failure. The event status object indicates how the job finished,
      * and the reason for failure, if applicable.
      *
      * @param event the event details
      */
     public void done(IJobChangeEvent event);

     /**
      * Notification that a job has started running.
      *
      * @param event the event details
      */
     public void running(IJobChangeEvent event);

     /**
      * Notification that a job is being added to the queue of scheduled jobs.
      * The event details includes the scheduling delay before the job should start
      * running.
      *
      * @param event the event details, including the job instance and the scheduling
      * delay
      */
     public void scheduled(IJobChangeEvent event);

     /**
      * Notification that a job was waiting to run and has now been put in the
      * sleeping state.
      *
      * @param event the event details
      */
     public void sleeping(IJobChangeEvent event);
 }

